This proposal focuses on two aims of PA-11-006: Substance Use and Abuse, Risky Decision Making and HIV/AIDS: 1) How does substance use shift the contribution of explicit (effortful) versus implicit (automatic) processes in decision-making about HIV-risk behavior, and 2) How do laboratory methods and simulations relate to real world risky behavior? The study incorporates an innovative pairing of an alcohol administration experiment with a subsequent experience sampling (ESM) study to test the external validity of the laboratory results. Interventions designed to reduce HIV risk behavior frequently focus on educating people about risks, increasing their motivation to avoid risks, and improving skills congruent with healthy choice. However, there are considerable gaps in knowledge about the processes involved in risky choice during the heat of the moment. Incorporating research on automatic processes, implicit cognition, and associative memory into the study and prevention of health risk behaviors is an important and largely unrealized opportunity for improving public health (Stacy et al., 2010). Automatic evaluations and approach biases can be successfully retrained via conditioning, resulting in corresponding changes in behavior (Chen & Bargh, 1999; Houben et al., 2010; Wiers et al., 2010). Research in diverse fields supports a dual-process model of self-control. Such models posit that self-control consists of two dimensions, a fast acting, reflexive, automatic dimension and a slower acting, deliberative or effortful dimension (Lieberman, 2007; Wiers et al., 2007). Automatic, reflexive, control emphasizes affective processes, while the effortful control dimension may consist largely of higher-order executive control processes (Lieberman, 2007). Risky sexual behavior may result when the strength of automatic approach behaviors exceeds the strength of deliberative cognitive control processes. The proposed experimental study seeks to improve understanding of the role of alcohol, implicit processes, and effortful control in risky sexual choice in men who have sex with men (MSM). We propose that alcohol intoxication increases the strength of relatively automatic approach biases toward sexual stimuli while simultaneously decreasing the role of more deliberative decision-making processes controlled by executive brain functions. This shift toward more implicit or automatic processes coupled with the decreased role of explicit decision- making processes increases the likelihood of sexual risk behavior and potentially limits the effectiveness of interventions that focus solely on explicit processes to promote behavioral change. The long-term aim of this research is explicating processes occurring in the heat of the moment when an individual's better judgment seems conspicuously absent and the drive for immediate gratification peaks. The proposed study will lay a foundation for innovative approaches to treatment that address both automatic and effortful processes to reduce sexual risk behavior in MSM.